The present invention relates to aircraft lighting. It in particular relates to an exterior aircraft light unit and, more particularly, to an exterior aircraft light unit having multiple light sources.
Almost all aircraft are equipped with exterior light units. In particular, large passenger air planes are provided with a wide variety of exterior light units. The exterior light units are provided for a wide variety of different purposes, such as for allowing the passengers and/or air crew to view the outside, for passive visibility, for signaling purposes, etc. Examples of such exterior light units are navigation lights, also referred to as position lights, beacon lights, anti-collision lights, wing scan lights, landing lights, taxi lights, runway turn-off lights, etc.
Each of said exterior light units may comprise a plurality of light sources. When operated, the temperature of said light sources increases. The temperature of the light sources, in particular of LEDs, however, needs to be restricted to avoid damage of the light sources and to operate the light sources with good efficiency. Thus, often heat sinks are provided in thermal connection with the light sources for dissipating the heat generated by operating the light sources. Ideally, the heat sinks would be designed so that the thermal loads/temperatures of all light sources of an exterior light unit are the same in order to allow operating all light sources simultaneously with good efficiency. For practical reasons, such as the mounting position and/or the spatial orientation of the exterior light unit, the heat sinks are often not ideal in real life exterior light units, so that the thermal loads/temperatures of the light sources of an exterior light unit are not the same. As a result, not all light sources of the exterior light unit may be operated simultaneously with good efficiency.
It therefore would be beneficial to provide an exterior aircraft light unit, having a plurality of light sources, which allows for simultaneously operating all light sources at good thermal conditions.